Jaciążek was formerly part of the German Empire. In the German Empire, the place was called Jaziaschek.
The place is now called Jaciążek and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Jaciazek | Russian Empire | Makov | 1914 |
| Jaciążek | Poland | Maków | 1919 |
| Jaziaschek | German Empire | Mackeim | 1939 |
| Jaciążek | Poland | Maków Mazowiecki | 1945 |
| Jaciążek | Poland | Ostrołęka | 1992 |